FZUS61 KBUF 171410 GLFLO Open Lake Forecast for Lake Ontario National Weather Service Buffalo NY 1009 AM EDT Fri Apr 17 2026 For waters beyond five nautical miles of shore on Lake Ontario Waves are the significant wave height - the average of the highest 1/3 of the wave spectrum. Occasional wave height is the average of the highest 1/10 of the wave spectrum. .SYNOPSIS...A 30.0 inch high over the Lake this evening will slide east into New England tonight. Meanwhile, a 29.4 inch low near Lake Superior this evening will move to James Bay and deepen to 29.0 inches Saturday, while pushing a trailing strong cold front across the Lake later Saturday and Saturday evening. A 30.4 inch high will then settle southeastward across the Great Lakes Sunday through Monday night, before sliding off the mid-Atlantic coast Tuesday. A 29.4 inch low over lower Hudson Bay Tuesday, will weaken to 29.9 inches by Wednesday, while pushing an attendant weak cold front across the Lake Tuesday night. A 30.2 inch high will then build across the Great Lakes region Wednesday and Thursday. LOZ062-172100- Lake Ontario open waters from the Niagara River to Hamlin Beach- 1009 AM EDT Fri Apr 17 2026 .THIS AFTERNOON...North winds less than 10 knots becoming east. Areas of fog. Waves 1 foot or less. .TONIGHT...East winds 10 knots or less becoming southeast. Waves 1 foot or less. .SATURDAY...Southeast winds 10 to 15 knots becoming southwest 15 to 20 knots. A chance of showers in the morning, then showers in the afternoon. Waves 1 to 3 feet building to 2 to 4 feet. .SATURDAY NIGHT...West winds 15 to 20 knots becoming northwest. Rain showers in the evening, then rain showers likely overnight. Waves 3 to 5 feet. .SUNDAY...West winds 15 to 20 knots becoming northwest. A chance of rain showers. Waves 3 to 5 feet. .MONDAY...Northwest winds 15 to 20 knots becoming southwest 5 to 15 knots. Waves 3 to 5 feet subsiding to 1 to 3 feet. .TUESDAY...South winds 15 to 20 knots becoming west 10 to 15 knots. Waves 1 to 3 feet building to 2 to 4 feet. $$ LOZ063>065-172100- Lake Ontario open waters from Hamlin Beach to the Saint Lawrence River- 1009 AM EDT Fri Apr 17 2026 .THIS AFTERNOON...North winds 5 to 10 knots becoming northwest. Patchy fog. Waves 1 foot or less. .TONIGHT...West winds 10 knots or less becoming southeast 10 to 15 knots. Waves 1 foot or less. .SATURDAY...Southeast winds 15 to 20 knots becoming south. Showers in the afternoon. Waves 1 to 3 feet building to 3 to 5 feet. .SATURDAY NIGHT...South winds 15 to 20 knots becoming west. Rain showers. Waves 3 to 5 feet. .SUNDAY...West winds 15 to 25 knots becoming northwest. Rain showers during the day. Waves 3 to 6 feet building to 4 to 7 feet. Waves occasionally around 9 feet. .MONDAY...Northwest winds 15 to 20 knots becoming west. Waves 3 to 6 feet subsiding to 2 to 4 feet. .TUESDAY...South winds 15 to 20 knots becoming southwest. A chance of rain showers Tuesday night. Waves 1 to 3 feet building to 2 to 4 feet. $$ LOZ061-172100- MAFOR 1715/ ONTARIO WEST 1/2 11100 14200 11300 12310. Waves 1 foot or less this afternoon and tonight. Waves 1 to 3 feet Saturday morning. ONTARIO EAST 1/2 11800 12700 13300 11310 11320. Waves 1 foot or less this afternoon and tonight. Waves 1 to 3 feet building to 2 to 4 feet Saturday morning. $$